The present invention is related generally to a method and article of manufacture of low fat, low cholesterol and low calorie process cheese products. More particularly, the invention is concerned with a method of manufacturing various low fat, low cholesterol and low calorie real process cheeses, such as Process American, Process Mozzarella and Provolone. Such process cheeses exhibit the appropriate functionality in terms of melting, stretching, slicing and shredding, as well as having good taste associated with typical higher fat process cheeses.
The general public has become increasingly aware of the need to control the intake of fats and cholesterol in their diets. Dairy products, particularly cheese products are regarded as a significant source of saturated fats and cholesterol. Medical studies have concluded that human consumption of such fats and cholesterol should be limited in order to avoid such maladies as coronary heart disease. The general recommendation has thus been to greatly reduce and even eliminate consumption of cheese which is a concentrated source of such detrimental, unhealthy fats and cholesterol. This recommendation is rapidly becoming accepted by the public and is resulting in substantial decrease in the consumption of cheese food products. Substantial efforts have been mounted over about the past ten years to discover a method and article of manufacture of low fat, low cholesterol cheese generally having the flavor and texture of normal cheese. It has been determined that the presence of fat is important in obtaining the right body and texture of the finished cheese, and the fat also has an important role in the flavor of the cheese product. All of these features affect consumer acceptability of the product. As stated by the cheese expert Kosikowski in his textbook on cheesemaking, Cheese and Fermented Milk Foods, F. V. Kosikowski and Associates, Brooktondale, New York, 1978 2nd ed.:
In this diet and calorie conscious era, skim milk cheddar cheese would appear to be destined for greater popularity, but the fact is that the cheese has no appetizing characteristics. It is without much cheese flavor and body texture is usually as hard as rock. Rapid drying out of the cheese during cooking is a characteristic feature, despite the normal low cooking temperatures of 31.degree. C. (Kosikowski, p. 242)
Imitation cheeses have been regarded as an inferior food because such cheeses do not use natural milk, instead using casein derived from milk proteins obtained by chemical processing. In addition, imitation cheese includes numerous chemicals and additives which make the labelled contents less appealing to the health-conscious consumer. Recently the United Dairy Association awarded the "Real" seal to dairy products containing natural milk ingredients. The consumer correlates the "Real" seal with high quality which has an important effect on the marketability of imitation cheeses.
Process cheeses typically contain an oil phase consisting of fats and oil soluble proteins and minerals. The two phases are not naturally compatible and thus in order to produce a quality product, the manufacturing process requires modification by surface active proteins. Surface active proteins are generally soluble in both the oil and water phases. One end region of the casein protein contains calcium phosphate groups and carries essentially all of the protein charge, while the other end is organic and non polar in nature. The phosphate end is water soluble while the organic end is fat soluble. It is generally believed this feature gives these proteins their emulsifying properties. The protein/fat ratio of process cheese is thus quite important in determining proper processing conditions to achieve the desired texture of the finished product. Emulsifying proteins are not very soluble in water, tending to clump and form grainy deposits. Therefore, fat free process cheeses are normally grainy and hard in texture. This can be compared to high fat process cheeses in which one end of the protein will dissolve in the fat while the other end will dissolve in the water, resulting in a homogeneous product. In low fat cheese there is not enough fat to accommodate all the proteins. The excess proteins will then separate into grainy or chalky water phase deposits. It is also very difficult to impart desirable cheese flavors in a conventional fat free process because of the absence of fats and because the fats are still the major source of flavor in fat containing cheeses.
Another difficulty in the prior art is the poor melting characteristics of conventional low fat cheeses. Typically, such low fat cheeses are prepared from curds having a pH in excess of 5.5. Such curd has poor melting properties, usually melts at higher temperatures and results in a heavy product which melts with difficulty and cannot be pumped very well. These problems are believed to derive at least in part from the presence of excessive calcium.